xref: /linux/arch/mips/include/asm/io.h (revision feb4eb060c3aecc3c5076bebe699cd09f1133c41)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1994, 1995 Waldorf GmbH
7  * Copyright (C) 1994 - 2000, 06 Ralf Baechle
8  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
9  * Copyright (C) 2004, 2005  MIPS Technologies, Inc.  All rights reserved.
10  *	Author: Maciej W. Rozycki <macro@mips.com>
11  */
12 #ifndef _ASM_IO_H
13 #define _ASM_IO_H
14 
15 #define ARCH_HAS_IOREMAP_WC
16 
17 #include <linux/compiler.h>
18 #include <linux/kernel.h>
19 #include <linux/types.h>
20 #include <linux/irqflags.h>
21 
22 #include <asm/addrspace.h>
23 #include <asm/barrier.h>
24 #include <asm/bug.h>
25 #include <asm/byteorder.h>
26 #include <asm/cpu.h>
27 #include <asm/cpu-features.h>
28 #include <asm-generic/iomap.h>
29 #include <asm/page.h>
30 #include <asm/pgtable-bits.h>
31 #include <asm/processor.h>
32 #include <asm/string.h>
33 
34 #include <ioremap.h>
35 #include <mangle-port.h>
36 
37 /*
38  * Raw operations are never swapped in software.  OTOH values that raw
39  * operations are working on may or may not have been swapped by the bus
40  * hardware.  An example use would be for flash memory that's used for
41  * execute in place.
42  */
43 # define __raw_ioswabb(a, x)	(x)
44 # define __raw_ioswabw(a, x)	(x)
45 # define __raw_ioswabl(a, x)	(x)
46 # define __raw_ioswabq(a, x)	(x)
47 # define ____raw_ioswabq(a, x)	(x)
48 
49 # define __relaxed_ioswabb ioswabb
50 # define __relaxed_ioswabw ioswabw
51 # define __relaxed_ioswabl ioswabl
52 # define __relaxed_ioswabq ioswabq
53 
54 /* ioswab[bwlq], __mem_ioswab[bwlq] are defined in mangle-port.h */
55 
56 #define IO_SPACE_LIMIT 0xffff
57 
58 /*
59  * On MIPS I/O ports are memory mapped, so we access them using normal
60  * load/store instructions. mips_io_port_base is the virtual address to
61  * which all ports are being mapped.  For sake of efficiency some code
62  * assumes that this is an address that can be loaded with a single lui
63  * instruction, so the lower 16 bits must be zero.  Should be true on
64  * on any sane architecture; generic code does not use this assumption.
65  */
66 extern unsigned long mips_io_port_base;
67 
68 static inline void set_io_port_base(unsigned long base)
69 {
70 	mips_io_port_base = base;
71 }
72 
73 /*
74  * Provide the necessary definitions for generic iomap. We make use of
75  * mips_io_port_base for iomap(), but we don't reserve any low addresses for
76  * use with I/O ports.
77  */
78 
79 #define HAVE_ARCH_PIO_SIZE
80 #define PIO_OFFSET	mips_io_port_base
81 #define PIO_MASK	IO_SPACE_LIMIT
82 #define PIO_RESERVED	0x0UL
83 
84 /*
85  * Enforce in-order execution of data I/O.  In the MIPS architecture
86  * these are equivalent to corresponding platform-specific memory
87  * barriers defined in <asm/barrier.h>.  API pinched from PowerPC,
88  * with sync additionally defined.
89  */
90 #define iobarrier_rw() mb()
91 #define iobarrier_r() rmb()
92 #define iobarrier_w() wmb()
93 #define iobarrier_sync() iob()
94 
95 /*
96  *     virt_to_phys    -       map virtual addresses to physical
97  *     @address: address to remap
98  *
99  *     The returned physical address is the physical (CPU) mapping for
100  *     the memory address given. It is only valid to use this function on
101  *     addresses directly mapped or allocated via kmalloc.
102  *
103  *     This function does not give bus mappings for DMA transfers. In
104  *     almost all conceivable cases a device driver should not be using
105  *     this function
106  */
107 static inline unsigned long virt_to_phys(volatile const void *address)
108 {
109 	return __pa(address);
110 }
111 
112 /*
113  *     phys_to_virt    -       map physical address to virtual
114  *     @address: address to remap
115  *
116  *     The returned virtual address is a current CPU mapping for
117  *     the memory address given. It is only valid to use this function on
118  *     addresses that have a kernel mapping
119  *
120  *     This function does not handle bus mappings for DMA transfers. In
121  *     almost all conceivable cases a device driver should not be using
122  *     this function
123  */
124 static inline void * phys_to_virt(unsigned long address)
125 {
126 	return (void *)(address + PAGE_OFFSET - PHYS_OFFSET);
127 }
128 
129 /*
130  * ISA I/O bus memory addresses are 1:1 with the physical address.
131  */
132 static inline unsigned long isa_virt_to_bus(volatile void *address)
133 {
134 	return virt_to_phys(address);
135 }
136 
137 static inline void *isa_bus_to_virt(unsigned long address)
138 {
139 	return phys_to_virt(address);
140 }
141 
142 /*
143  * However PCI ones are not necessarily 1:1 and therefore these interfaces
144  * are forbidden in portable PCI drivers.
145  *
146  * Allow them for x86 for legacy drivers, though.
147  */
148 #define virt_to_bus virt_to_phys
149 #define bus_to_virt phys_to_virt
150 
151 /*
152  * Change "struct page" to physical address.
153  */
154 #define page_to_phys(page)	((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
155 
156 extern void __iomem * __ioremap(phys_addr_t offset, phys_addr_t size, unsigned long flags);
157 extern void __iounmap(const volatile void __iomem *addr);
158 
159 static inline void __iomem * __ioremap_mode(phys_addr_t offset, unsigned long size,
160 	unsigned long flags)
161 {
162 	void __iomem *addr = plat_ioremap(offset, size, flags);
163 
164 	if (addr)
165 		return addr;
166 
167 #define __IS_LOW512(addr) (!((phys_addr_t)(addr) & (phys_addr_t) ~0x1fffffffULL))
168 
169 	if (cpu_has_64bit_addresses) {
170 		u64 base = UNCAC_BASE;
171 
172 		/*
173 		 * R10000 supports a 2 bit uncached attribute therefore
174 		 * UNCAC_BASE may not equal IO_BASE.
175 		 */
176 		if (flags == _CACHE_UNCACHED)
177 			base = (u64) IO_BASE;
178 		return (void __iomem *) (unsigned long) (base + offset);
179 	} else if (__builtin_constant_p(offset) &&
180 		   __builtin_constant_p(size) && __builtin_constant_p(flags)) {
181 		phys_addr_t phys_addr, last_addr;
182 
183 		phys_addr = fixup_bigphys_addr(offset, size);
184 
185 		/* Don't allow wraparound or zero size. */
186 		last_addr = phys_addr + size - 1;
187 		if (!size || last_addr < phys_addr)
188 			return NULL;
189 
190 		/*
191 		 * Map uncached objects in the low 512MB of address
192 		 * space using KSEG1.
193 		 */
194 		if (__IS_LOW512(phys_addr) && __IS_LOW512(last_addr) &&
195 		    flags == _CACHE_UNCACHED)
196 			return (void __iomem *)
197 				(unsigned long)CKSEG1ADDR(phys_addr);
198 	}
199 
200 	return __ioremap(offset, size, flags);
201 
202 #undef __IS_LOW512
203 }
204 
205 /*
206  * ioremap_prot     -   map bus memory into CPU space
207  * @offset:    bus address of the memory
208  * @size:      size of the resource to map
209 
210  * ioremap_prot gives the caller control over cache coherency attributes (CCA)
211  */
212 static inline void __iomem *ioremap_prot(phys_addr_t offset,
213 		unsigned long size, unsigned long prot_val) {
214 	return __ioremap_mode(offset, size, prot_val & _CACHE_MASK);
215 }
216 
217 /*
218  * ioremap     -   map bus memory into CPU space
219  * @offset:    bus address of the memory
220  * @size:      size of the resource to map
221  *
222  * ioremap performs a platform specific sequence of operations to
223  * make bus memory CPU accessible via the readb/readw/readl/writeb/
224  * writew/writel functions and the other mmio helpers. The returned
225  * address is not guaranteed to be usable directly as a virtual
226  * address.
227  */
228 #define ioremap(offset, size)						\
229 	__ioremap_mode((offset), (size), _CACHE_UNCACHED)
230 
231 /*
232  * ioremap_nocache     -   map bus memory into CPU space
233  * @offset:    bus address of the memory
234  * @size:      size of the resource to map
235  *
236  * ioremap_nocache performs a platform specific sequence of operations to
237  * make bus memory CPU accessible via the readb/readw/readl/writeb/
238  * writew/writel functions and the other mmio helpers. The returned
239  * address is not guaranteed to be usable directly as a virtual
240  * address.
241  *
242  * This version of ioremap ensures that the memory is marked uncachable
243  * on the CPU as well as honouring existing caching rules from things like
244  * the PCI bus. Note that there are other caches and buffers on many
245  * busses. In particular driver authors should read up on PCI writes
246  *
247  * It's useful if some control registers are in such an area and
248  * write combining or read caching is not desirable:
249  */
250 #define ioremap_nocache(offset, size)					\
251 	__ioremap_mode((offset), (size), _CACHE_UNCACHED)
252 #define ioremap_uc ioremap_nocache
253 
254 /*
255  * ioremap_cachable -	map bus memory into CPU space
256  * @offset:	    bus address of the memory
257  * @size:	    size of the resource to map
258  *
259  * ioremap_nocache performs a platform specific sequence of operations to
260  * make bus memory CPU accessible via the readb/readw/readl/writeb/
261  * writew/writel functions and the other mmio helpers. The returned
262  * address is not guaranteed to be usable directly as a virtual
263  * address.
264  *
265  * This version of ioremap ensures that the memory is marked cachable by
266  * the CPU.  Also enables full write-combining.	 Useful for some
267  * memory-like regions on I/O busses.
268  */
269 #define ioremap_cachable(offset, size)					\
270 	__ioremap_mode((offset), (size), _page_cachable_default)
271 #define ioremap_cache ioremap_cachable
272 
273 /*
274  * ioremap_wc     -   map bus memory into CPU space
275  * @offset:    bus address of the memory
276  * @size:      size of the resource to map
277  *
278  * ioremap_wc performs a platform specific sequence of operations to
279  * make bus memory CPU accessible via the readb/readw/readl/writeb/
280  * writew/writel functions and the other mmio helpers. The returned
281  * address is not guaranteed to be usable directly as a virtual
282  * address.
283  *
284  * This version of ioremap ensures that the memory is marked uncachable
285  * but accelerated by means of write-combining feature. It is specifically
286  * useful for PCIe prefetchable windows, which may vastly improve a
287  * communications performance. If it was determined on boot stage, what
288  * CPU CCA doesn't support UCA, the method shall fall-back to the
289  * _CACHE_UNCACHED option (see cpu_probe() method).
290  */
291 #define ioremap_wc(offset, size)					\
292 	__ioremap_mode((offset), (size), boot_cpu_data.writecombine)
293 
294 static inline void iounmap(const volatile void __iomem *addr)
295 {
296 	if (plat_iounmap(addr))
297 		return;
298 
299 #define __IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
300 
301 	if (cpu_has_64bit_addresses ||
302 	    (__builtin_constant_p(addr) && __IS_KSEG1(addr)))
303 		return;
304 
305 	__iounmap(addr);
306 
307 #undef __IS_KSEG1
308 }
309 
310 #if defined(CONFIG_CPU_CAVIUM_OCTEON) || defined(CONFIG_CPU_LOONGSON3)
311 #define war_io_reorder_wmb()		wmb()
312 #else
313 #define war_io_reorder_wmb()		barrier()
314 #endif
315 
316 #define __BUILD_MEMORY_SINGLE(pfx, bwlq, type, barrier, relax, irq)	\
317 									\
318 static inline void pfx##write##bwlq(type val,				\
319 				    volatile void __iomem *mem)		\
320 {									\
321 	volatile type *__mem;						\
322 	type __val;							\
323 									\
324 	if (barrier)							\
325 		iobarrier_rw();						\
326 	else								\
327 		war_io_reorder_wmb();					\
328 									\
329 	__mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));	\
330 									\
331 	__val = pfx##ioswab##bwlq(__mem, val);				\
332 									\
333 	if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
334 		*__mem = __val;						\
335 	else if (cpu_has_64bits) {					\
336 		unsigned long __flags;					\
337 		type __tmp;						\
338 									\
339 		if (irq)						\
340 			local_irq_save(__flags);			\
341 		__asm__ __volatile__(					\
342 			".set	push"		"\t\t# __writeq""\n\t"	\
343 			".set	arch=r4000"			"\n\t"	\
344 			"dsll32 %L0, %L0, 0"			"\n\t"	\
345 			"dsrl32 %L0, %L0, 0"			"\n\t"	\
346 			"dsll32 %M0, %M0, 0"			"\n\t"	\
347 			"or	%L0, %L0, %M0"			"\n\t"	\
348 			"sd	%L0, %2"			"\n\t"	\
349 			".set	pop"				"\n"	\
350 			: "=r" (__tmp)					\
351 			: "0" (__val), "m" (*__mem));			\
352 		if (irq)						\
353 			local_irq_restore(__flags);			\
354 	} else								\
355 		BUG();							\
356 }									\
357 									\
358 static inline type pfx##read##bwlq(const volatile void __iomem *mem)	\
359 {									\
360 	volatile type *__mem;						\
361 	type __val;							\
362 									\
363 	__mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));	\
364 									\
365 	if (barrier)							\
366 		iobarrier_rw();						\
367 									\
368 	if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
369 		__val = *__mem;						\
370 	else if (cpu_has_64bits) {					\
371 		unsigned long __flags;					\
372 									\
373 		if (irq)						\
374 			local_irq_save(__flags);			\
375 		__asm__ __volatile__(					\
376 			".set	push"		"\t\t# __readq" "\n\t"	\
377 			".set	arch=r4000"			"\n\t"	\
378 			"ld	%L0, %1"			"\n\t"	\
379 			"dsra32 %M0, %L0, 0"			"\n\t"	\
380 			"sll	%L0, %L0, 0"			"\n\t"	\
381 			".set	pop"				"\n"	\
382 			: "=r" (__val)					\
383 			: "m" (*__mem));				\
384 		if (irq)						\
385 			local_irq_restore(__flags);			\
386 	} else {							\
387 		__val = 0;						\
388 		BUG();							\
389 	}								\
390 									\
391 	/* prevent prefetching of coherent DMA data prematurely */	\
392 	if (!relax)							\
393 		rmb();							\
394 	return pfx##ioswab##bwlq(__mem, __val);				\
395 }
396 
397 #define __BUILD_IOPORT_SINGLE(pfx, bwlq, type, barrier, relax, p)	\
398 									\
399 static inline void pfx##out##bwlq##p(type val, unsigned long port)	\
400 {									\
401 	volatile type *__addr;						\
402 	type __val;							\
403 									\
404 	if (barrier)							\
405 		iobarrier_rw();						\
406 	else								\
407 		war_io_reorder_wmb();					\
408 									\
409 	__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
410 									\
411 	__val = pfx##ioswab##bwlq(__addr, val);				\
412 									\
413 	/* Really, we want this to be atomic */				\
414 	BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));		\
415 									\
416 	*__addr = __val;						\
417 }									\
418 									\
419 static inline type pfx##in##bwlq##p(unsigned long port)			\
420 {									\
421 	volatile type *__addr;						\
422 	type __val;							\
423 									\
424 	__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
425 									\
426 	BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));		\
427 									\
428 	if (barrier)							\
429 		iobarrier_rw();						\
430 									\
431 	__val = *__addr;						\
432 									\
433 	/* prevent prefetching of coherent DMA data prematurely */	\
434 	if (!relax)							\
435 		rmb();							\
436 	return pfx##ioswab##bwlq(__addr, __val);			\
437 }
438 
439 #define __BUILD_MEMORY_PFX(bus, bwlq, type, relax)			\
440 									\
441 __BUILD_MEMORY_SINGLE(bus, bwlq, type, 1, relax, 1)
442 
443 #define BUILDIO_MEM(bwlq, type)						\
444 									\
445 __BUILD_MEMORY_PFX(__raw_, bwlq, type, 0)				\
446 __BUILD_MEMORY_PFX(__relaxed_, bwlq, type, 1)				\
447 __BUILD_MEMORY_PFX(__mem_, bwlq, type, 0)				\
448 __BUILD_MEMORY_PFX(, bwlq, type, 0)
449 
450 BUILDIO_MEM(b, u8)
451 BUILDIO_MEM(w, u16)
452 BUILDIO_MEM(l, u32)
453 #ifdef CONFIG_64BIT
454 BUILDIO_MEM(q, u64)
455 #else
456 __BUILD_MEMORY_PFX(__raw_, q, u64, 0)
457 __BUILD_MEMORY_PFX(__mem_, q, u64, 0)
458 #endif
459 
460 #define __BUILD_IOPORT_PFX(bus, bwlq, type)				\
461 	__BUILD_IOPORT_SINGLE(bus, bwlq, type, 1, 0,)			\
462 	__BUILD_IOPORT_SINGLE(bus, bwlq, type, 1, 0, _p)
463 
464 #define BUILDIO_IOPORT(bwlq, type)					\
465 	__BUILD_IOPORT_PFX(, bwlq, type)				\
466 	__BUILD_IOPORT_PFX(__mem_, bwlq, type)
467 
468 BUILDIO_IOPORT(b, u8)
469 BUILDIO_IOPORT(w, u16)
470 BUILDIO_IOPORT(l, u32)
471 #ifdef CONFIG_64BIT
472 BUILDIO_IOPORT(q, u64)
473 #endif
474 
475 #define __BUILDIO(bwlq, type)						\
476 									\
477 __BUILD_MEMORY_SINGLE(____raw_, bwlq, type, 1, 0, 0)
478 
479 __BUILDIO(q, u64)
480 
481 #define readb_relaxed			__relaxed_readb
482 #define readw_relaxed			__relaxed_readw
483 #define readl_relaxed			__relaxed_readl
484 #ifdef CONFIG_64BIT
485 #define readq_relaxed			__relaxed_readq
486 #endif
487 
488 #define writeb_relaxed			__relaxed_writeb
489 #define writew_relaxed			__relaxed_writew
490 #define writel_relaxed			__relaxed_writel
491 #ifdef CONFIG_64BIT
492 #define writeq_relaxed			__relaxed_writeq
493 #endif
494 
495 #define readb_be(addr)							\
496 	__raw_readb((__force unsigned *)(addr))
497 #define readw_be(addr)							\
498 	be16_to_cpu(__raw_readw((__force unsigned *)(addr)))
499 #define readl_be(addr)							\
500 	be32_to_cpu(__raw_readl((__force unsigned *)(addr)))
501 #define readq_be(addr)							\
502 	be64_to_cpu(__raw_readq((__force unsigned *)(addr)))
503 
504 #define writeb_be(val, addr)						\
505 	__raw_writeb((val), (__force unsigned *)(addr))
506 #define writew_be(val, addr)						\
507 	__raw_writew(cpu_to_be16((val)), (__force unsigned *)(addr))
508 #define writel_be(val, addr)						\
509 	__raw_writel(cpu_to_be32((val)), (__force unsigned *)(addr))
510 #define writeq_be(val, addr)						\
511 	__raw_writeq(cpu_to_be64((val)), (__force unsigned *)(addr))
512 
513 /*
514  * Some code tests for these symbols
515  */
516 #ifdef CONFIG_64BIT
517 #define readq				readq
518 #define writeq				writeq
519 #endif
520 
521 #define __BUILD_MEMORY_STRING(bwlq, type)				\
522 									\
523 static inline void writes##bwlq(volatile void __iomem *mem,		\
524 				const void *addr, unsigned int count)	\
525 {									\
526 	const volatile type *__addr = addr;				\
527 									\
528 	while (count--) {						\
529 		__mem_write##bwlq(*__addr, mem);			\
530 		__addr++;						\
531 	}								\
532 }									\
533 									\
534 static inline void reads##bwlq(volatile void __iomem *mem, void *addr,	\
535 			       unsigned int count)			\
536 {									\
537 	volatile type *__addr = addr;					\
538 									\
539 	while (count--) {						\
540 		*__addr = __mem_read##bwlq(mem);			\
541 		__addr++;						\
542 	}								\
543 }
544 
545 #define __BUILD_IOPORT_STRING(bwlq, type)				\
546 									\
547 static inline void outs##bwlq(unsigned long port, const void *addr,	\
548 			      unsigned int count)			\
549 {									\
550 	const volatile type *__addr = addr;				\
551 									\
552 	while (count--) {						\
553 		__mem_out##bwlq(*__addr, port);				\
554 		__addr++;						\
555 	}								\
556 }									\
557 									\
558 static inline void ins##bwlq(unsigned long port, void *addr,		\
559 			     unsigned int count)			\
560 {									\
561 	volatile type *__addr = addr;					\
562 									\
563 	while (count--) {						\
564 		*__addr = __mem_in##bwlq(port);				\
565 		__addr++;						\
566 	}								\
567 }
568 
569 #define BUILDSTRING(bwlq, type)						\
570 									\
571 __BUILD_MEMORY_STRING(bwlq, type)					\
572 __BUILD_IOPORT_STRING(bwlq, type)
573 
574 BUILDSTRING(b, u8)
575 BUILDSTRING(w, u16)
576 BUILDSTRING(l, u32)
577 #ifdef CONFIG_64BIT
578 BUILDSTRING(q, u64)
579 #endif
580 
581 static inline void memset_io(volatile void __iomem *addr, unsigned char val, int count)
582 {
583 	memset((void __force *) addr, val, count);
584 }
585 static inline void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
586 {
587 	memcpy(dst, (void __force *) src, count);
588 }
589 static inline void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
590 {
591 	memcpy((void __force *) dst, src, count);
592 }
593 
594 /*
595  * The caches on some architectures aren't dma-coherent and have need to
596  * handle this in software.  There are three types of operations that
597  * can be applied to dma buffers.
598  *
599  *  - dma_cache_wback_inv(start, size) makes caches and coherent by
600  *    writing the content of the caches back to memory, if necessary.
601  *    The function also invalidates the affected part of the caches as
602  *    necessary before DMA transfers from outside to memory.
603  *  - dma_cache_wback(start, size) makes caches and coherent by
604  *    writing the content of the caches back to memory, if necessary.
605  *    The function also invalidates the affected part of the caches as
606  *    necessary before DMA transfers from outside to memory.
607  *  - dma_cache_inv(start, size) invalidates the affected parts of the
608  *    caches.  Dirty lines of the caches may be written back or simply
609  *    be discarded.  This operation is necessary before dma operations
610  *    to the memory.
611  *
612  * This API used to be exported; it now is for arch code internal use only.
613  */
614 #ifdef CONFIG_DMA_NONCOHERENT
615 
616 extern void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
617 extern void (*_dma_cache_wback)(unsigned long start, unsigned long size);
618 extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
619 
620 #define dma_cache_wback_inv(start, size)	_dma_cache_wback_inv(start, size)
621 #define dma_cache_wback(start, size)		_dma_cache_wback(start, size)
622 #define dma_cache_inv(start, size)		_dma_cache_inv(start, size)
623 
624 #else /* Sane hardware */
625 
626 #define dma_cache_wback_inv(start,size) \
627 	do { (void) (start); (void) (size); } while (0)
628 #define dma_cache_wback(start,size)	\
629 	do { (void) (start); (void) (size); } while (0)
630 #define dma_cache_inv(start,size)	\
631 	do { (void) (start); (void) (size); } while (0)
632 
633 #endif /* CONFIG_DMA_NONCOHERENT */
634 
635 /*
636  * Read a 32-bit register that requires a 64-bit read cycle on the bus.
637  * Avoid interrupt mucking, just adjust the address for 4-byte access.
638  * Assume the addresses are 8-byte aligned.
639  */
640 #ifdef __MIPSEB__
641 #define __CSR_32_ADJUST 4
642 #else
643 #define __CSR_32_ADJUST 0
644 #endif
645 
646 #define csr_out32(v, a) (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST) = (v))
647 #define csr_in32(a)    (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST))
648 
649 /*
650  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
651  * access
652  */
653 #define xlate_dev_mem_ptr(p)	__va(p)
654 
655 /*
656  * Convert a virtual cached pointer to an uncached pointer
657  */
658 #define xlate_dev_kmem_ptr(p)	p
659 
660 void __ioread64_copy(void *to, const void __iomem *from, size_t count);
661 
662 #endif /* _ASM_IO_H */
663